DE 43 11 886 A1 has disclosed a device and a method by means of which an automatically shifting transmission can be operated with one selector device or a first automatic operating mode and one selector device for a second operating mode controlled by the driver which is also called a manual shifting mode. Between the automatic shifting mode and the manual shifting mode, it is possible with the first selector device to shift by moving a selector lever of the first selector device from a position D to a position M or by a shifting signal being delivered by means of a second selector device which can be designed as a rocker or any other shifting means.
It is, likewise, provided that by means of both selector devices a change from the manual shifting mode to the automatic shifting mode be possible, the selector lever having to be moved from the position M to a position D or a signal of the second selector device has to abut over a preset time period in order to produce a change of the operating mode.
If the vehicle reaches operating limits detectable for the device in which, for example, an overspeeding or a stalling of the engine occurs for the precisely introduced gear of the transmission, a gear shift is triggered even without a shift command of the driver in order to bring the vehicle back to the admissible operating limits. It is further provided that after lapse of a preset period of time without a new manual shifting command of the driver, the manual shifting mode is quit and the automatic shifting mode activated.
In DE 197 09 506 A1 has been described an automatic transmission of a motor vehicle in which a manual shifting instead of an automatic shifting can be carried out. In an automatic shifting, a controller selects an adequate reduction ratio according to a vehicle speed and a degree of opening of throttle valve.
If the driver wishes a manual shifting and moves a shift lever to an M range position, the controller designs a control program in order to carry out a manual shifting operation in the M range. Depending on preset operating states of the vehicle, particularly of the engine and of the automatic transmission, it is determined in a manual shifting mode whether critical operating states have been reached which require an automatic shifting. If a corresponding question results in that such critical operating states have been reached, in a very low speed of the vehicle, for example, a forced downshift is automatically introduced and in case of a high speed of the vehicle, which goes along with a high rotational speed of the engine, a forced upshift is automatically carried out.
Those solutions known from the prior art for change between an automatic shifting mode and a manual shifting mode have, however, the disadvantage that they proceed time gated and only take into consideration—if at all—certain operating situations. Besides, they afford only insufficient shifting comfort to the driver.
The problem of insufficient shifting comfort exists in those solutions known from the practice in which, together with a selector lever movable in a selector lever gate in two directions (+/−) for upshifting or downshifting, a shift control is provided as an added selector device for so-called “inching shift” in which it is possible to shift by tapping an adequate sensor, for example, on a steering wheel, to the next lower or next higher speed. By actuating one such inching switch to the steering wheel, if the driver activates the manual shifting mode in the solutions known from the practice for changing to the automatic operation, he has to move usually the selector lever in the selector lever gate for manual operation and reset it again out of said position.
The problem on which this invention is based is to make a method for control of an automatically shifting vehicle transmission available with which an individual adaptation of the control of a vehicle transmission to the existing operating situation and driving style of the driver concerned can be carried out while ensuring a good driving stability of the vehicle and with greater operating comfort for the driver.
This problem is solved according to the invention with a method having the features of claim 1.